Copyright is very complex and is sometimes dependent when the original was created.
Generally for written (literary) works it last until 70 years from the end of the year following the death of the author. This still applies where the author is an employee (e.g. of Audi) and his/her contract of employment assigns the rights to the employer. Only once the 70 years has expired does the works become "public domain". Even then, if someone copies it and publishes their copy then their copy is copyright for 25 years after the year of their publication (e.g. modern reprints of old music or the Bible).
This is UK law. The Berne Convention is life of the author plus 50 years from death. German law may well be longer as in the UK.
Plenty of websites explain this.
Some companies are actively pursuing those who post copies of their technical manuals on the internet as they want to protect their repair franchises from loosing work to cheaper servicing companies or they simply want to force users to buy new items when old items break (not very green).
Fuel Consumption for 1.4 TDi 75 SE: <sorry deleted - will try to reinstate>
Mostly A(T), A or B roads.
Was 62.5 mpg with Pilot Primacy Michelins 185/50/16 18V
Then 58 mpg with Pirrelli P6000 Powergy but they are much quieter.
Next 62 mpg after 5th gear change to 0.65 (Skipton) & remap of +20 bhp (Stealth) on a 4,000 mile European trip.
Now Toyo Proxes T1R - also quiet.
Changed matt black slatted grill for the glossy black smooth grill.